By E, KNA
The Government has confirmed that a preliminary assessment conducted after a sink hole emerged along the Nakuru-Eldoret-Kisumu Highway at Eveready area in Nakuru has not compromised the integrity of the road.
Secretary for Geological Survey in the Ministry of Mining, Blue Economy and Maritime Affairs, Enock Kipseba, assured motorists using the road of their safety, indicating that it had been reopened after extensive assessment and backfilling.
The Secretary explained that the sink-hole was occasioned by geological activity beneath the surface which he said remains unpredictable.
The sink hole followed an incident where heavy rains were witnessed after which runoff water collected at the scene before the ground caved in, sending panic among residents and motorists.
This is the second time a similar phenomenon has been witnessed at the same site, raising concerns about safety of the road and surrounding residential areas.
Mr Kipseba however assured that the government will establish a local geo-hazard observatory for real time monitoring and geo-physical monitoring of the area.
He also urged motorists to exercise caution while approaching the Eveready roundabout on the A8 Road due to earlier noted geological activities that had undermined the road shoulder and which he said could potentially recur, especially with the on-going rains.
Mr Kipseba who spoke after a joint team from the Ministry of Mining, Blue Economy and Maritime Affairs, the Kenya National Highways Authority (KeNHA) and the County Government of Nakuru toured the site, added that together with other relevant government agencies, it will continue monitoring the situation and conduct an in-depth investigation with the assistance of geologists to address the issue.
In the meantime, he urged motorists to observe traffic signs and rules to ensure the safety of all road users.
Mr Kipseba stated that engineers and geologists were working on the occurrences in Nakuru, which he said had a volcanic history of sinkholes.
“We presume that this area has a historical fault line. The back filling of the hole is in progress even as we wait for further advice from experts on a possible long-term solution,” he added.
The official further disclosed that they were employing ground penetrating radar, seismic electronics and electric magnet technology to assess the extent of the fault line.
“We are witnessing a pyroduct that has existed in this area for centuries. The rains caused overlying material to collapse, causing deep gullies that have progressed towards the road,” Kipseba explained.
A pyroduct is an empty tube-like structure which molten lava uses as an exit during volcanic action, and similar features exist in most of Nakuru county linked to the nearby Menengai Crater.
Mr Kipseba explained that a pyroduct is surrounded by pyroclastic material which is easily affected by the flow of water. He indicated that the interim solution was to check the flow of the water that ends up in the micro tunnels to avoid their collapse.
Director Maintenance at KeNHA, Engineer Fukwo Wafula confirmed the sinkhole was caused by water seepage and geological activity, prompting authorities to take urgent safety measures.
Engineer Wafula said the area’s instability was attributed to volcanic activity during the formation of the Rift Valley, leaving a layer of pumice or volcanic ash that covers numerous fault lines.
“Beneath the surface, the region consists of loose ash sand, which can be easily washed away by water percolation,” he explained.
He further added that the Rift Valley’s fault lines were not uniform in size, which contributes to the frequent formation of sinkholes, especially during heavy rains or poor drainage.
Geologists have repeatedly warned that the rapid construction of skyscrapers in Nakuru could be a disaster waiting, as the unstable ground may fail to support the weight in the event of a natural disaster such as a landslip or an earthquake.
Engineer Wafula assured that the authority said it is working with other government agencies and geologists to investigate the problem and will continue monitoring the road.
“Motorists are advised to exercise caution as they approach the area and follow directions from traffic police and marshals to ensure the safety of all road users,” he warned.
Scientifically, sinkholes are defined as depressions in the ground that are caused by the collapse of a surface layer, often taking place with little to no warning.
Sinkholes can range in size from a few feet to several meters in depth and width. The sudden nature of their occurrence inevitably poses a serious risk to infrastructure and vehicles.